Creating a single-carbon vacancy introduces (quasi-)localized states for both σ and π electrons in graphene. Theoretically, interactions between the localized σ electrons and quasilocalized π electrons of a single-carbon vacancy in graphene are predicted to control its magnetism. However, experimentally confirming this prediction through manipulating the interactions remains an outstanding challenge. Here we report the manipulation of magnetism in the vicinity of an individual single-carbon vacancy in graphene by using a scanning tunnelling microscopy (STM) tip. Our spin-polarized STM measurements, complemented by density functional theory calculations, indicate that the interactions between the localized σ and quasilocalized π electrons could split the π electrons into two states with opposite spins even when they are well above the Fermi level. Via the STM tip, we successfully manipulate both the magnitude and direction of magnetic moment of the π electrons with respect to that of the σ electrons. Three different magnetic states of the single-carbon vacancy, exhibiting magnetic moments of about 1.6 μ_B, 0.5 μ_B, and 0 μ_B respectively, are realized in our experiment.

创建单碳空位会为石墨烯中的 σ 和 π 电子引入（准）局域态。从理论上讲，预计石墨烯中单碳空位的局域 σ 电子和准局域 π 电子之间的相互作用将控制其磁性。然而，通过操纵相互作用通过实验证实这一预测仍然是一个突出的挑战。在这里，我们通过使用扫描隧道显微镜 (STM) 尖端报告了石墨烯中单个单碳空位附近的磁性操纵。我们的自旋极化 STM 测量，辅之以密度泛函理论计算，表明局部 σ 和准局部 π 电子之间的相互作用可以将 π 电子分裂成两个具有相反自旋的状态，即使它们远高于费米能级。通过 STM 尖端，我们成功地控制了 π 电子相对于 σ 电子磁矩的大小和方向。单碳空位的三种不同磁态，磁矩约为 1.6 μ_B、0.5 μ _B和 0 μ _B分别在我们的实验中实现。